Constraint management in Li-ion batteries: A modified reference governor approach

This paper addresses the problem of satisfying state constraints in Li-ion batteries, to maintain safe operation and prolong battery life. Mathematically, these constraints are formulated from a first principles electrochemical model. Consequently, the constraints explicitly model specific degradation mechanisms, such as lithium plating, lithium depletion, overheating, and stress fracture. The critical challenges, however, are that (i) these states evolve according to a system of nonlinear partial differential equations, and (ii) the states are not physically measurable. This paper focuses on the first challenge by utilizing the reference governor concept. The results demonstrate how electrochemical model state information can be utilized to ensure safe operation, while providing opportunities to enhance energy capacity, power, and charge times in Li-ion batteries.